In HTML, numbers and letters do not wrap to show __html

Transferred from https://www.cnblogs.com/yiran2016/p/6169168.html

The numbers and letters in the HTML tag are not wrapped by default, and if you want to wrap them, add "Word-wrap:break-word" to the CSS to resolve the 

syntax: Word-wrap:normal|break-word;

Default normal: The word is not broken by default, long words will overflow
Break-word: Will first start a new line to place long words, the new line or not put this long word will be forced to sentence long words.

if necessary, word wrapping is used (word-break) to

Grammar: word-break:break-all; do not put long words in a new line, when this line can not put down when the direct forced punctuation.

For example

<! DOCTYPE html>